1. Field of the Invention
The present invention relates to a thin film magnetic head comprising at least an inductive magnetic transducer for recording, a method of manufacturing the same, and a magnetic recording apparatus such as, for example, a hard disk drive which comprises the thin film magnetic head.
2. Description of the Related Art
In recent years, magnetic recording apparatuses such as, for example, hard disk drives have been in widespread use as recording sources of various information. In the development of hard disk drives, an improvement in performance of thin film magnetic heads has been sought in accordance with an increase in the areal density of a magnetic recording medium (hereinafter simply referred to as “recording medium”), that is, a hard disk. As magnetic recording systems applicable to thin film magnetic heads, for example, a longitudinal recording system that a signal magnetic field is oriented in an in-plane direction of a recording medium (a longitudinal direction) and a perpendicular recording system that the signal magnetic field is oriented in a direction perpendicular to a surface of the recording medium are well-known. At present, the longitudinal recording system is widely used, but in consideration of market forces in accordance with an improvement in areal density, the perpendicular recording system instead of the longitudinal recording system holds promise for future, because the perpendicular recording system can obtain an advantage that higher liner recording density can be achieved, and a recording medium in which data has been already recorded has resistance to thermal decay effects.
As recording modes using the perpendicular recording system, for example, (1) a mode of using a head (ring type head) facing each other with a gap in between on a side of an end and being magnetically coupled to each other on a side of the other end, and a single-layer recording medium and (2) a mode of using a head (single pole type head) being disposed perpendicular to a recording medium and a two-layer recording medium have been proposed. In these modes, based upon a point that the mode using a combination of the single pole type head and the two-layer recording medium has superior resistance to thermal decay, the mode becomes a focus of attention as a mode which can improve the performance of thin film magnetic heads.
In order to improve the recording performance of the perpendicular recording system thin film magnetic head, for example, it is required to reduce an influence of a problem resulting from a skew of the head as much as possible. The skew means that during operation of the hard disk drive, the thin film magnetic head is disposed so as to be inclined in a direction tangential to the circumference of a hard disk. When the head is skewed, mainly resulting from a structural factor of the thin film magnetic head, expansion or bending of a recording pattern may occur. When the expansion or the bending of the recording pattern occurs, a cross talk to an adjacent track occurs, thereby an error rate during reproducing increases, so the recording performance declines.
However, in a conventional perpendicular recording system thin film magnetic head, in consideration of a movement of areal density which is expected to be rapidly increased more and more in future, measures to reduce the expansion and the bending of the recording pattern when the skew occurs is still not sufficient. Further, when the thin film magnetic head is designed with consideration for reduction in the expansion and the bending of the recording pattern resulting from the skew, it is important that with consideration for mass productivity of the thin film magnetic head, the thin film magnetic head can be manufactured as easily as possible without complicating manufacturing techniques.